P
US6353424B2ExpiredUtilityPatentIndex 82

Display apparatus capable of adjusting subfield number according to brightness

Assignee: MATSUSHITA ELECTRIC INDUSTRIAL CO LTDPriority: Dec 10, 1997Filed: Feb 21, 2001Granted: Mar 5, 2002
Est. expiryDec 10, 2017(expired)· nominal 20-yr term from priority
Inventors:KASAHARA MITSUHIROISHIKAWA YUICHIMORITA TOMOKO
G09G 3/34G09G 3/2022G09G 2360/144G09G 2320/0266G09G 3/2803G09G 3/2037G09G 2330/021G09G 2320/0261G09G 3/2033G09G 2320/106G09G 2320/041G09G 2320/0276G09G 2360/16G09G 3/294G09G 2320/0626G09G 3/291G09G 3/296
82
PatentIndex Score
10
Cited by
34
References
11
Claims

Abstract

A display apparatus adjusts the brightness of a plasma display panel. The display apparatus comprises an adjusting device, which acquires image brightness data, and adjusts the number of subfields Z on the basis of brightness data.

Claims

exact text as granted — not AI-modified
What is claimed is:  
     
       1. A display apparatus for creating, for each image, a number of subfields Z from a first subfield to a Zth subfield in accordance with a Z bit representation of each pixel, a weight of each subfield, and a number of gradation display points, the display apparatus comprising: 
       a panel temperature detector that detects a temperature of a display panel displaying the image;  
       an image characteristic determining device that determines a subfield number Z and a weighing multiple, while maintaining a same number of gradation display points, based on the temperature of the display panel; and  
       a weight setting device that multiplies the weight of each subfield by the weighing multiple;  
       wherein the image characteristic determining device decreases the subfield number Z and increases the weighing multiple as the temperature of the display panel decreases.  
     
     
       2. The display apparatus according to  claim 1 , wherein the image characteristic determining device determines a multiplication factor for amplifying an image signal, based on the temperature of the display panel displaying the image, the image characteristic determining device comprising a multiplier for amplifying the image signal by the multiplication factor. 
     
     
       3. The display apparatus according to  claim 2 , wherein the image characteristic determining device decreases the multiplication factor as the temperature increases. 
     
     
       4. The display apparatus according to  claim 1 , further comprising: 
       an average level detector that detects an average image brightness level, and  
       the image characteristic determining device determining the subfield Z and the weighing multiple, while maintaining the same number of gradation display points, based on the average image brightness level detected by the average level detector, and on the temperature of the display panel detected by the panel temperature detector.  
     
     
       5. A display method for creating, for each image, a number of subfields Z from a first subfield to a Zth subfield in accordance with a Z bit representation of each pixel, a weight of each subfield, and a number of gradation display points, the display method comprising: 
       detecting a temperature of a display panel displaying the image;  
       determining a subfield number Z and a weighing multiple, while maintaining a same number of gradation display points, based on the temperature of the display panel; and  
       multiplying the weight of each subfield by the weighing multiple,  
       wherein the subfield number Z decreases and the weighing multiple increases as the temperature of the display panel decreases.  
     
     
       6. The display method according to  claim 5 , wherein the determining determines a multiplication factor for amplifying an image signal, based on the temperature of the display panel, and the display method further comprising multiplying the image signal by the multiplication factor to amplify the image signal. 
     
     
       7. The display method according to  claim 5 , wherein the determining decreases the multiplication factor as the temperature of the display panel increases. 
     
     
       8. The display method according to  claim 5 , further comprising detecting an average image brightness level, and wherein the determining determines the subfield number Z and the weighing multiple, while maintaining the same number of gradation display points, based on the detected average image brightness level and the detected temperature. 
     
     
       9. A display apparatus for creating, for each image, a number of subfields Z from a first subfield to a Zth subfield in accordance with a Z bit representation of each pixel, a weight of each subfield, and a number of gradation display points, the display apparatus comprising: 
       a panel temperature detector that detects a temperature of a display panel displaying the image;  
       an image characteristic determining device that determines a subfield number Z and a weighing multiple based on the temperature of the display panel; and  
       a weight setting device that multiplies the weight of each subfield by the weighing multiple,  
       wherein the image characteristic determining device decreases the weighing multiple as the temperature of the display panel increases.  
     
     
       10. The display apparatus according to  claim 9 , wherein the image characteristic determining device determines a multiplication factor for amplifying an image signal, based on the temperature of the display panel, the image characteristic determining device comprising a multiplier for amplifying the image signal by the multiplication factor. 
     
     
       11. The display apparatus according to  claim 10 , wherein the image characteristic determining device decreases the multiplication factor as the temperature of the display panel increases.

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